Portion of a display screen with a graphical user interface



The single view is a front view of a portion of a display screen with a graphical user interface.

The broken lines showing a portion of a display screen form no part of the claimed design. The remaining broken lines showing text and portions of the graphical user interface form no part of the claimed design. 

CLAIM The ornamental design for a portion of a display screen with a graphical user interface, as shown and described. 